ORA-12560: TNS:protocol adapter error(TNS:协议适配器错误)

这种问题一般是因为客户端不知道要连那个instance或者不知道要使用哪个TNS Alias

可能的原因1.服务没有起来

下边是Tom的一个Test Case来说明OracleServiceSID服务没有起来的话，是会引起ORA-12560错误的。

C:\Documents and Settings\tkyte>sqlplus scott/tigerSQL*Plus: Release 10.1.0.4.0 - Production on Thu Sep 6 15:43:55 2007Copyright (c) 1982, 2005, Oracle.  All rights reserved.Connected to:Oracle Database 10g Enterprise Edition Release 10.1.0.4.0 - ProductionWith the Partitioning, OLAP and Data Mining optionsscott%ORA10GR1> exitDisconnected from Oracle Database 10g Enterprise Edition Release 10.1.0.4.0 - ProductionWith the Partitioning, OLAP and Data Mining optionsC:\Documents and Settings\tkyte>net stop oracleserviceora10gr1The OracleServiceORA10GR1 service is stopping.........The OracleServiceORA10GR1 service was stopped successfully.C:\Documents and Settings\tkyte>sqlplus scott/tigerSQL*Plus: Release 10.1.0.4.0 - Production on Thu Sep 6 15:44:35 2007Copyright (c) 1982, 2005, Oracle.  All rights reserved.ERROR:ORA-12560: TNS:protocol adapter errorEnter user-name:ERROR:ORA-12560: TNS:protocol adapter errorEnter user-name:ERROR:ORA-12560: TNS:protocol adapter errorSP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*PlusC:\Documents and Settings\tkyte>net start oracleserviceora10gr1The OracleServiceORA10GR1 service is starting..........The OracleServiceORA10GR1 service was started successfully.C:\Documents and Settings\tkyte>sqlplus scott/tigerSQL*Plus: Release 10.1.0.4.0 - Production on Thu Sep 6 15:45:12 2007Copyright (c) 1982, 2005, Oracle.  All rights reserved.Connected to:Oracle Database 10g Enterprise Edition Release 10.1.0.4.0 - ProductionWith the Partitioning, OLAP and Data Mining optionsscott%ORA10GR1>

修改方法：控制面板>管理工具>服务里边把OracleServiceSID起起来

可能的原因2.ORACLE_SID环境变量没有指定（最常见引起ORA-12560问题的原因）

检查方法，命令行(cmd)下，

C:\Documents and Settings\ptian>set oracle_sid
ORACLE_SID=test

ORACLE_SID是sqlplus默认连接的数据库instance,即sqlplus user/pwd连接的instance，如果不指定sqlplus里连接的时候就需要明确@你的instance,eg,sqlplus user/pwd@instance.

修改方法：在注册表中，HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_OraDb10g_home1\ORACLE_SID 需指向你的Instance(eg.orcl)；或者在系统的环境变量里加ORACLE_SID项，值为Instance的SID。

可能的原因3.TNS_ADMIN环境变量没有指定

检查方法，命令行(cmd)下，

C:\Documents and Settings\ptian>set TNS_ADMIN
TNS_ADMIN=D:\oracle\product\10.1.0\Db_1\NETWORK\ADMIN

TNS_ADMIN应该返回你的tnsnames.ora所在的目录

修改方法：可以在注册表HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\HOME0\TNS_ADMIN或者环境变量中指定。

可能的原因4.ORACLE_HOME环境变量没有指定

和上边的方法类似，检查Oracle_Home环境变量

可能的原因5.tnsnames.ora文件内容不对

A sample:

TEST =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = ptian-cn.cn.oracle.com)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = test)
    )
  )

Possible fixes for the TNS-12560 include：

转载请注明出处：http://blog.csdn.net/pan_tian/article/details/7699469

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